U.S. Pat. No. 4,377,062 A describes a corn picker, in which a screw conveyor is arranged above the picking rolls. This screw conveyor conveys the plant stalks into and through the picking gap. A lower gathering wheel is located beneath the picking gap at the inlet side, i.e., the side of the picking gap located opposite the screw conveyor. An upper gathering wheel is arranged above the screw conveyor coaxially to the lower gathering wheel. The gathering wheels serve for conveying the plants into the picking gap.
DE 100 28 887 A describes another corn harvesting attachment, in which a gathering element that rotates about an approximately vertical axis and is provided with approximately radial carrier elements grasps the stalks of plants standing in a field and conveys said stalks along the picking gap of a picking device. Due to the utilization of a rotating gathering element, operating width is increased in comparison with conventional pickers that operate with gathering chains, since plants that stand laterally adjacent to the picking gap are also gathered. Since the gathering element also moves the plants through the picking gap, the structural length is relatively short. In order to prevent possible conveyance problems when the plants are introduced into the picking gap, another conveying element in the form of a screw conveyor or a chain conveyor that introduces the plants into the picking gap is arranged on the side of the picking gap located opposite the gathering element. However, conveyance problems may still arise under certain harvesting conditions.